Tuesday, August 31, 2010

Split Identity: The Flower Crab is Now Four and Other Stories

Life has changed slightly now that I am a full-time graduate student. This allows me a little time during 'office hours' for some research blogging to resurrect this space.

Hot off the press today with lots of interesting new findings is the latest issue of the Raffles Bulletin of Zoology published by the Raffles Museum of Biodiversity Research. I'll highlight two that papers that are closest to my heart.

Male crabs formerly known as Portunus pelagicus. Photo J. Lai.

The first, A Revision of the Portunus pelagicus (Linnaeus, 1758) species complex (Crustacea: Brachyura: Portunidae), with the recognition of four species by Lai et al. found that the crab formerly known as the swimming (or more commonly known in markets as 'flower') crab, P. pelagicus actually has a split identity - it is made up of four similar-looking species.

A species complex is a group of closely related species where scientists are unable to clearly differentiate. Traditionally, taxonomist use a selection of form or appearance to identify and classify organisms. This however, becomes increasingly tricky with very similar looking specimens. Using newer techniques such as molecular phylogenetics to complement morphology, scientist are now able to analyse characters and differences at genetic level and thus shed more light on species within a complex.

Based on morphology and DNA characters, the authors split the original flower crab into 4 species: P. pelagicus from Southeast and East Asia to Northern Australia; P. armatus circum Australia; and P. reticulatus and P. segnis slightly separated in the Eastern and Western Indian Ocean respectively.

It is interesting is that the original P. pelagicus was first described by Carl Linnaeus, the father of modern day scientific classification, and what Linnaeus did not have at that time is the sophisticated DNA analysis technology and know-how that is available today. We have come a long way since then. Now, what would this finding hold in the commercial realm...

Banded leaf monkey carrying infant. Photo A. Ang.

The next paper by Ang et al. records the Reproduction and Infant Pelage Colouration of the Banded Leaf Monkey (Mammalia: Primates: Cercopithecidae) in Singapore.

Prior to the study, little was known about the ecology of the banded leaf monkey (Presbytis femoralis) in Singapore. There were also reports of orange-coloured infants by scientists and veteran naturalists which is not characteristic of the species.

The authors spent 843 hours in the field and confirmed from at least 6 births that infant monkeys are born white, with black markings on the back (dorsum). This is consistent with the same species in Johor, Malaysia.

I had the pleasure of following the first author during their field trips and found that these monkeys were indeed difficult to study and follow due to their shyness and the forebodingly thick, spiky vegetation and boggy terrain. Despite this, Andie has been doggedly following them for the past one and a half years to collect these important natural history information about our local monkeys.

In addition, she collected data on their diet, genetic information from their feces and population size. All of which would contribute to the conservation of the species which now looks more optimistic for one which was formerly said to be doomed to extinction here.


  1. Lai, J. C. Y., P. K. L. Ng, P. J. F. Davie. 2010. A Revision of the Portunus pelagicus (Linnaeus, 1758) species complex (Crustacea: Brachyura: Portunidae), with the recognition of four species. Raffles Bulletin of Zoology 58(2): 199-237.
  2. Ang, A., M. R. B. Ismail, R. Meier. 2010. Reproduction and Infant Pelage Colouration of the Banded Leaf Monkey (Mammalia: Primates: Cercopithecidae) in Singapore. Raffles Bulletin of Zoology 58(2): 411-415.